Burner



Dec. 1, 1942.

D. E, LEMSTER ETAL BURNER Filed Oct. 2. 1941 E5 if i g W & 65

5 E n v x Q sv ma 0. hwy MW I & Q w sm Q wwwm hot sheet mill pack furnaces.

Patented Dec. 1, 1942 UNITED STATES PATENTOFFICE BURNER Devon E. Lemster and Thomas R. Owens, a

Gary, Ind.

Application October 2, 1941, Serial No. 413,352

2 Claims.

The present invention relates to a type of burner which, while not limited thereto, is 'peculiarly well suited for use in connection with Such furnaces as heretofore constructed are efllcient only so long as the steelbeing heated was within the confined-limits of type size and weight for which given burners were designed. Heretofor'e efficient heating of the product was dependent upon maintaining a high flame velocity. and furnace atmosphere which was recirculated through the heating and combustion chambers of the furnace. When the burner rating was reduced in order to prevent overheating of a light product, flame velocity dropped; thus the heating was not uniform and was inefficient. Likewise, when a heavy product was being heated in the' furnaces for which low capacity burners were provided, the furnace'output was correspondingly very low. To meet this condition each time it was desired to change the capacity of the furnace it was necessary to alter the burners. which was a wasteful practice resulting in considerable nonproductive'time and expense.

The burners heretofore used' were equipped with air outlet orifices in the nozzle of fixed size, and in order to increase the burner capacity the burner had to be removed and the total area of the air nozzle orifices increased. n the other hand, to lower the burner capacity it was necessary to remove the burner and replace the air nozzle with one containing orifices of a smaller area. These changes and alterations entailed shutting down of the furnace and thus putting it out of production for a consequential time interval and also involved the labor and expense of reconstructing the burners.

The burner of the present invention aims to overcome the above and other objectionable features of prior art burners. To this end the burner of our invention is designed to maintain constant flame velocity through the complete range of capacities required by a wide variety of products to be heated. This increases the flexibility of the furnaces in which the burners are used and eliminates lost time due to shut downs heretofore necessary in order to change the air nozzles in conventional burners.

The present invention consists of the particular combination of coacting elements, all of which are combined and coordinated in the manner herein shown, described and specifically claimed.

For a full and complete understanding of the characteristics of the present improvement, reference is to be made to the following description,

the accompanying drawings and the appended claims.

In the drawings:

Figure l is a longitudinal vertical section through the burner of the present invention;

Figure 2 is an enlarged detail of parts shown in Figure 1;

Figure 3 is a fragmentary detail view partly in section on line III-III of Figure 1 of certain essential elements of the invention; and

Figure 4 is a detail section on line IV-IV of Figure l. l

Referring in detail to the drawing, the numeral Ill "represents an oil supply pipe which connects with a liquid fuel burner pipe l2, the supply of liquid .fuel being under control of a valve 14. Surrounding the pipe l2 there is a pipe I6 which is supplied with atomizing steam through the fitting 20 by the supply pipe 18 under control of a valve 10. The atomized liquid fuel is discharged from a burner tip 22 in a manner well known to those skilled in the art.

Surrounding the pipe Hi there is a fuel pipe 24 which is connected to a fitting 26 which in turn communicates with a gaseous fuel supply pipe 28. A valve H controls the supply of gaseous fuel.

The foregoing liquid and gaeous fuel supplies are of conventional form and are not herein claimed per se apart from the combination.

Commercial grades of fuel oil are supplied at from 10 to 50 pounds pressure and are atomized by steam at from 15 to 50 pounds pressure. When natural gas is used, the same .is supplied at a pressure of 1 to 10 pounds. In some cases a combination of both natural gas and atomized liquid fuel may be used.

Heretofore the amount of air supplied to support combustion has been controlled by the combined area of a series of apertures formed. in a nozzle portion of the burner and in order to change the rating of the burner it has been necessary to either substitute a burner with different size air outlet ports or to reconstruct the burner by substituting a part containing air outlet ports of requisite size. The present invention overcomes this costly and cumbersome time-consuming practice. To this end we provide a shell 30 which surrounds the fuel pipe 24. At its discharge end the burner of our invention is provided with a disc 32 which is secured by a weld seam 34 to the inner extremity of said shell 30. At its outer extremity the shell 30 has a ring otherwise secured an end closure plate 38. The

shell is formed with a laterally extended branch 40 leading to an air supply pipe 42 which is connected with a suitable fan or blower.

The disc 32 has a plurality of circularly arranged outlet ports 44 formed therein which are preferably tapered. Projecting through each outlet port there is a tapered tip member 46 preferably formed of stainless steel. The disc 32 is also preferably formed of stainless steel, this material being desirable since it resists rust and corrosion and prevents clogging of the orifices by corrosive action of furnace gases.

Each tip 46 is welded or otherwise secured to a shank 48 of reduced diameter formed on the inner extremity of a rod 50.. The several rods 50 are mounted with freedom for limited longitudin'al movement in guides 52 carried by spider arms 54 radiating from a spider hub 56 welded or otherwise secured to the fuel pipe 24.

Each of the rods 50 is screw threaded as indicated at 58 for coaction with correspondingly threaded feed nuts 60 fixedly secured to the plate 38. A pinion 62 is fixedly secured by a set screw 64 or the like to the outer extremity'of each rod 50. The several pinions 62 mesh with a common operating gear 66 which has a hand wheel 68 secured thereto, the gear and the hand wheel being rotatable in unison about the axis of the fuel pipe 24.

With the parts as above constructed and arranged, all that is required to change the capacity of the improved burner is to operate the hand wheel 68 to turn the gear 66. This will simultaneously rotate all of the pinions 62 and thus either advance or retract the adjusting rods 50 because of the coaction of the threaded portions 58 of the rods with the feed nuts 60. This will either advance or retract the tapered tips 46 which project into the tapered-air ports 44. This will result in either decreasing or increasing the total area of the ports in the nozzle portion of the burner, depending; of course, upon whether the rods are retracted from the disc 32 or advanced toward it. Thus the flame velocity and furnace atmosphere recirculation are held constant by compensating for changed air volumes by increasing or decreasing the total area of the air ports in the nozzle portion of the burner. The increased effectiveness of the burner shown and described is made available whether using either gas or oil as fuel or whether using a combination of gas and oil. The parts as shown and described are of simple design and of sturdy construction. Thus the burners are inexpensive to build and maintain and have a relatively long life.

While we have described quite specifically the burner herein illustrated, it is to be understood that various modifications and changes may be made and that the appended claims are to .be construed as broadly as is consistent with the prior state of the ar We claim:

1. A burner of the character described comprising a longitudinally extending fuel pipe, a

nozzle disc secured to the'discharge end thereof, a

a piatespaced from the latter and secured to said pipe, a shell surrounding said pipe and closed at its opposite/ends by said disc and said plate, said shellhaving an air inlet connection, said disc having a plurality of air outlet ports therein, tapered members projecting into said ports, means supporting said members with freedom for longitudinal adjustment relative to said disc, and means for simultaneously imparting a longitudinal adjusting movement to all said tapered members so as to vary the effective outlet area of all said air ports. a

2. A burner of the character described comprising alongitudinally extending fuel pipe, a

.nozzle disc secured to the discharge end thereof,

a plate spaced from the latter and secured to said pipe, a shell surrounding saidpipe and closed at its opposite ends by said disc and said plate, said shell having an air inlet branch extendinglaterally therefrom, said disc having a plurality of circularly spaced air ports therein, respective tapered tips projecting into said ports, circularly spaced rods paralleling said fuel pipe for supporting said tips, a spider secured'to the fuel pipe having guides formed therein for said rods, each rod being provided with a screw threaded portion, respective feed nuts coacting with said threaded portions and secured to said plate, respectivepinions secured to said rods, and a gearrotatable about the axis of the fuel pipe engaging said pinions to simultaneously move all said tips relative to said ports to thus simultaneously vary the efiective air outlet areas thereof.

DEVON E. LEMSTER. THOMAS R.OWENS. 

